/****************************************************************************
 * net/bluetooth/bt_keys.c
 * Bluetooth key handling
 *
 *   Copyright (C) 2018 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Ported from the Intel/Zephyr arduino101_firmware_source-v1.tar package
 * where the code was released with a compatible 3-clause BSD license:
 *
 *   Copyright (c) 2016, Intel Corporation
 *   All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>

#include <string.h>
#include <debug.h>

#include <tinyara/bluetooth/bt_core.h>
#include <tinyara/bluetooth/bt_hci.h>

#include "bt_hcicore.h"
#include "bt_smp.h"
#include "bt_keys.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#define bt_keys_foreach(list, cur, member) \
	for (cur = list; *cur; cur = &(*cur)->member)

/****************************************************************************
 * Private Data
 ****************************************************************************/

static struct bt_keys_s g_key_pool[CONFIG_BLUETOOTH_MAX_PAIRED];

static FAR struct bt_keys_s *g_ltks;
static FAR struct bt_keys_s *g_slave_ltks;
static FAR struct bt_keys_s *g_irks;
static FAR struct bt_keys_s *g_local_csrks;
static FAR struct bt_keys_s *g_remote_csrks;

/****************************************************************************
 * Public Functions
 ****************************************************************************/

FAR struct bt_keys_s *bt_keys_get_addr(FAR const bt_addr_le_t *addr)
{
	FAR struct bt_keys_s *keys;
	int i;

	nvdbg("%s\n", bt_addr_le_str(addr));

	for (i = 0; i < CONFIG_BLUETOOTH_MAX_PAIRED; i++) {
		keys = &g_key_pool[i];

		if (!bt_addr_le_cmp(&keys->addr, addr)) {
			return keys;
		}

		if (!bt_addr_le_cmp(&keys->addr, BT_ADDR_LE_ANY)) {
			bt_addr_le_copy(&keys->addr, addr);
			nvdbg("created %p for %s\n", keys, bt_addr_le_str(addr));
			return keys;
		}
	}

	nvdbg("unable to create keys for %s\n", bt_addr_le_str(addr));

	return NULL;
}

void bt_keys_clear(FAR struct bt_keys_s *keys, int type)
{
	FAR struct bt_keys_s **cur;

	nvdbg("keys for %s type %d\n", bt_addr_le_str(&keys->addr), type);

	if (((type & keys->keys) & BT_KEYS_SLAVE_LTK)) {
		bt_keys_foreach(&g_slave_ltks, cur, slave_ltk.next) {
			if (*cur == keys) {
				*cur = (*cur)->slave_ltk.next;
				break;
			}
		}

		keys->keys &= ~BT_KEYS_SLAVE_LTK;
	}

	if (((type & keys->keys) & BT_KEYS_LTK)) {
		bt_keys_foreach(&g_ltks, cur, ltk.next) {
			if (*cur == keys) {
				*cur = (*cur)->ltk.next;
				break;
			}
		}

		keys->keys &= ~BT_KEYS_LTK;
	}

	if (((type & keys->keys) & BT_KEYS_IRK)) {
		bt_keys_foreach(&g_irks, cur, irk.next) {
			if (*cur == keys) {
				*cur = (*cur)->irk.next;
				break;
			}
		}

		keys->keys &= ~BT_KEYS_IRK;
	}

	if (((type & keys->keys) & BT_KEYS_LOCAL_CSRK)) {
		bt_keys_foreach(&g_local_csrks, cur, local_csrk.next) {
			if (*cur == keys) {
				*cur = (*cur)->local_csrk.next;
				break;
			}
		}

		keys->keys &= ~BT_KEYS_LOCAL_CSRK;
	}

	if (((type & keys->keys) & BT_KEYS_REMOTE_CSRK)) {
		bt_keys_foreach(&g_remote_csrks, cur, remote_csrk.next) {
			if (*cur == keys) {
				*cur = (*cur)->remote_csrk.next;
				break;
			}
		}

		keys->keys &= ~BT_KEYS_REMOTE_CSRK;
	}

	if (!keys->keys) {
		memset(keys, 0, sizeof(*keys));
	}
}

FAR struct bt_keys_s *bt_keys_find(int type, FAR const bt_addr_le_t *addr)
{
	FAR struct bt_keys_s **cur;

	nvdbg("type %d %s\n", type, bt_addr_le_str(addr));

	switch (type) {
	case BT_KEYS_SLAVE_LTK:
		bt_keys_foreach(&g_slave_ltks, cur, slave_ltk.next) {
			if (!bt_addr_le_cmp(&(*cur)->addr, addr)) {
				break;
			}
		}

		return *cur;

	case BT_KEYS_LTK:
		bt_keys_foreach(&g_ltks, cur, ltk.next) {
			if (!bt_addr_le_cmp(&(*cur)->addr, addr)) {
				break;
			}
		}

		return *cur;

	case BT_KEYS_IRK:
		bt_keys_foreach(&g_irks, cur, irk.next) {
			if (!bt_addr_le_cmp(&(*cur)->addr, addr)) {
				break;
			}
		}

		return *cur;

	case BT_KEYS_LOCAL_CSRK:
		bt_keys_foreach(&g_local_csrks, cur, local_csrk.next) {
			if (!bt_addr_le_cmp(&(*cur)->addr, addr)) {
				break;
			}
		}

		return *cur;

	case BT_KEYS_REMOTE_CSRK:
		bt_keys_foreach(&g_remote_csrks, cur, remote_csrk.next) {
			if (!bt_addr_le_cmp(&(*cur)->addr, addr)) {
				break;
			}
		}

		return *cur;

	default:
		return NULL;
	}
}

void bt_keys_add_type(FAR struct bt_keys_s *keys, int type)
{
	if ((keys->keys & type) != 0) {
		return;
	}

	switch (type) {
	case BT_KEYS_SLAVE_LTK:
		keys->slave_ltk.next = g_slave_ltks;
		g_slave_ltks = keys;
		break;

	case BT_KEYS_LTK:
		keys->ltk.next = g_ltks;
		g_ltks = keys;
		break;

	case BT_KEYS_IRK:
		keys->irk.next = g_irks;
		g_irks = keys;
		break;

	case BT_KEYS_LOCAL_CSRK:
		keys->local_csrk.next = g_local_csrks;
		g_local_csrks = keys;
		break;

	case BT_KEYS_REMOTE_CSRK:
		keys->remote_csrk.next = g_remote_csrks;
		g_remote_csrks = keys;
		break;

	default:
		ndbg("ERROR: Unknown key type %d\n", type);
		return;
	}

	keys->keys |= type;
}

FAR struct bt_keys_s *bt_keys_get_type(int type, FAR const bt_addr_le_t *addr)
{
	FAR struct bt_keys_s *keys;

	nvdbg("type %d %s\n", type, bt_addr_le_str(addr));

	keys = bt_keys_find(type, addr);
	if (keys) {
		return keys;
	}

	keys = bt_keys_get_addr(addr);
	if (!keys) {
		return NULL;
	}

	bt_keys_add_type(keys, type);
	return keys;
}

FAR struct bt_keys_s *bt_keys_find_irk(FAR const bt_addr_le_t *addr)
{
	FAR struct bt_keys_s **cur;

	nvdbg("%s\n", bt_addr_le_str(addr));

	if (!bt_addr_le_is_rpa(addr)) {
		return NULL;
	}

	bt_keys_foreach(&g_irks, cur, irk.next) {
		FAR struct bt_irk_s *irk = &(*cur)->irk;

		if (!bt_addr_cmp((bt_addr_t *) addr->val, &irk->rpa)) {
			nvdbg("cached RPA %s for %s\n", bt_addr_str(&irk->rpa), bt_addr_le_str(&(*cur)->addr));
			return *cur;
		}

		if (bt_smp_irk_matches(irk->val, (bt_addr_t *) addr->val)) {
			FAR struct bt_keys_s *match = *cur;

			nvdbg("RPA %s matches %s\n", bt_addr_str(&irk->rpa), bt_addr_le_str(&(*cur)->addr));

			bt_addr_copy(&irk->rpa, (bt_addr_t *) addr->val);

			/* Move to the beginning of the list for faster future lookups. */

			if (match != g_irks) {
				/* Remove match from list */

				*cur = irk->next;

				/* Add match to the beginning */

				irk->next = g_irks;
				g_irks = match;
			}

			return match;
		}
	}

	nvdbg("No IRK for %s\n", bt_addr_le_str(addr));
	return NULL;
}
